Wireless communication networks have seen an explosive data growth in past few years and, in the future, are expected to see continuing growth in the Packet Switched (PS) domain. In particular, Long Term Evolution (LTE) networks, defined by the Third Generation Partnership Project (3GPP), are being deployed by service providers in response to a growing user demand for higher data rates and higher quality of service. LTE technology supports packet-based services only; however, the 3GPP standards specify a fallback for circuit switched (CS) services. Moreover, the LTE architecture provides CS fallback by reusing a CS infrastructure for provisioning of voice and traditional CS-domain services. For example, when a LTE device initiates a voice call, the call can be routed through a Universal Mobile Telecommunications System (UMTS) network, overlaid with the LTE network. Typically, a CS fallback enabled device, connected to an evolved UMTS Terrestrial Radio Access Network (E-UTRAN), can utilize a UMTS Terrestrial Radio Access Network (UTRAN) to connect to the CS domain.
In general, the LTE systems are overlaid with UMTS systems that include UMTS femtocells. In this scenario, when a UMTS femtocell is co-channel with a UMTS macro cell, a conflict can arise during CS fallback. In particular, the 3GPP LTE specification defines UMTS neighbors by employing UMTS Absolute Radio Frequency Number (UARFCN) levels. In other words, when an LTE device performs CS fallback, the LTE system provides the device with the UARFCN information and additional measurement thresholds for device to scan/tune to/attach to a UMTS neighbor cell. Thus, for UMTS macro and femtocells that share a common UARFCN, the LTE device cannot differentiate between the UMTS macro cell and the UMTS femtocell. Oftentimes, users prefer to connect to a UMTS femtocell, for example, to take advantage of reduced billing, improved network coverage, etc. Accordingly, since the LTE device cannot identify UMTS femtocell neighbors, conflicts are created during handover. Moreover, during CS fallback, conventional LTE devices reselect carriers randomly between macro and femtocells, based only on UARFCN information, which can lead to user dissatisfaction. As an example, user dissatisfaction is due to Femto access control: which can add considerable CS fallback call setup delay and potential failure,
The above-described deficiencies of wireless systems are merely intended to provide an overview of some of the problems of conventional systems and techniques, and are not intended to be exhaustive. Other problems with conventional systems and techniques, and corresponding benefits of the various non-limiting embodiments described herein may become further apparent upon review of the following description.